iTeh StandardsiTeh Standards
EURUSD
Your shopping cart is empty.
ASTM

ASTM G98-02

(Test Method)

Standard Test Method for Galling Resistance of Materials

Standard Test Method for Galling Resistance of Materials

SIGNIFICANCE AND USE
This test method is designed to rank material couples in their resistance to the failure mode caused by galling and not merely to classify the surface appearance of sliding surfaces.
This test method should be considered when damaged (galled) surfaces render components non-serviceable. Experience has shown that galling is most prevalent in sliding systems that are slow moving and operate intermittently. The galling and seizure of threaded components is a classic example which this test method most closely simulates.
Other galling-prone examples include: sealing surfaces of value trim which may leak excessively due to galling; and pump wear rings that may function ineffectively due to galling.
If the equipment continues to operate satisfactorily and loses dimension gradually, then mechanical wear should be evaluated by a different test such as the crossed cylinder Test Method (see Test Method G 83). Chain belt pins and bushings are examples of this type of problem.
This test method should not be used for quantitative or final design purposes since many environmental factors influence the galling performance of materials in service. Lubrication, alignment, stiffness and geometry are only some of the factors that can affect how materials perform. This test method has proven valuable in screening materials for prototypical testing that more closely simulates actual service conditions.
SCOPE
1.1 This test method covers a laboratory test which ranks the galling resistance of material couples. Most galling studies have been conducted on bare metals and alloys; however, non-metallics, coatings, and surface modified alloys may also be evaluated by this test method.
1.2 This test method is not designed for evaluating the galling resistance of material couples sliding under lubricated conditions because galling usually will not occur under lubricated sliding conditions using this test method.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

Status
Historical
Publication Date
09-Nov-2002
ICS
17.040.20 - Properties of surfaces
Technical Committee
G02 - Wear and Erosion
Drafting Committee
G02.40 - Non-Abrasive Wear
Current Stage
Ref Project

Relations

Replaces
ASTM G98-91(1996)e1 - Standard Test Method for Galling Resistance of Materials
Effective Date
10-Nov-2002
Replaced By
ASTM G98-02(2009) - Standard Test Method for Galling Resistance of Materials
Effective Date
01-Oct-2009
Referred By
ASTM G196-08(2021) - Standard Test Method for Galling Resistance of Material Couples
Effective Date
10-Nov-2002

Buy Standard

ASTM G98-02 - Standard Test Method for Galling Resistance of MaterialsASTM G98-02 - Standard Test Method for Galling Resistance of Materials
PreviousNext
Standard
ASTM G98-02 - Standard Test Method for Galling Resistance of Materials
English language
4 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:G98–02
Standard Test Method for
1
Galling Resistance of Materials
This standard is issued under the fixed designation G98; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2 Definitions of Terms Specific to This Standard:
3.2.1 threshold galling stress—the stress midway between
1.1 This test method covers a laboratory test which ranks
the highest non-galled stress and the lowest galled stress as
the galling resistance of material couples. Most galling studies
determined by this test method.
have been conducted on bare metals and alloys; however,
non-metallics, coatings, and surface modified alloys may also
4. Summary of Test Method
be evaluated by this test method.
4.1 This test method uses available laboratory equipment
1.2 This test method is not designed for evaluating the
capable of maintaining a constant, compressive load between
galling resistance of material couples sliding under lubricated
two flat specimens, such as hydraulic or screw feed compres-
conditions because galling usually will not occur under lubri-
sion testing machines. One specimen is slowly rotated one
cated sliding conditions using this test method.
revolution360°relativetotheotherspecimen.Thesurfacesare
1.3 This standard does not purport to address all of the
examined for galling after sliding. The criterion for whether
safety concerns, if any, associated with its use. It is the
galling occurs is the appearance of the specimens based on
responsibility of the user of this standard to establish appro-
unassisted visual examination. If the specimens have not
priate safety and health practices and determine the applica-
galled, a new set of specimens is tested at increased load. This
bility of regulatory limitations prior to use.
process is continued until galling occurs.
2. Referenced Documents 4.2 Appropriate load intervals are chosen to determine the
2
threshold galling stress within an acceptable range.
2.1 ASTM Standards:
2
4.3 The higher the threshold galling stressing, the more
G40 Terminology Relating to Wear and Erosion
galling resistant is the test couple.
G83 Test Method for Wear Testing with a Crossed-Cylinder
3
Apparatus
5. Significance and Use
3. Terminology 5.1 This test method is designed to rank material couples in
their resistance to the failure mode caused by galling and not
3.1 Definition: Definition used in this test method is given in
merely to classify the surface appearance of sliding surfaces.
Terminology G40G40.
5.2 This test method should be considered when damaged
3.1.1 galling—a form of surface damage arising between
(galled) surfaces render components non-serviceable. Experi-
sliding solids, distinguished by macroscopic, usually localized,
ence has shown that galling is most prevalent in sliding
roughening and creation of protrusions above the original
systems that are slow moving and operate intermittently. The
surface; it often includes plastic flow or material transfer, or
galling and seizure of threaded components is a classic
both.
example which this test method most closely simulates.
3.1.1.1 Discussion—The onset of galling usually requires
5.3 Other galling-prone examples include: sealing surfaces
thatthecontactpressureexceedssomethresholdvalue.Galling
of value trim which may leak excessively due to galling; and
can be a precursor to seizing or loss of function. The identifi-
pump wear rings that may function ineffectively due to galling.
cation of galling is somewhat subjective, and complete agree-
5.4 If the equipment continues to operate satisfactorily and
ment does not exist, even among experts.
loses dimension gradually, then mechanical wear should be
evaluated by a different test such as the crossed cylinder Test
1
This test method is under the jurisdiction of ASTM Committee G02 on Wear
Method (see Test Method G83). Chain belt pins and bushings
and Erosion and is the direct responsibility of Subcommittee G02.40 on Non-
are examples of this type of problem.
Abrasive Wear.
5.5 This test method should not be used for quantitative or
Current edition approved Nov. 10, 2002. Published January 2003. Originally
approved in 1989. Last previous edition approved in 1996 as G98 – 91 (1996). DOI:
final design purposes since many environmental factors influ-
10.1520/G0098-02.
ence the galling performance of materials in service. Lubrica-
2
Annual Book of ASTM Standards, Vol 03.02.
3 tion, alignment, stiffness and geometry are only some of the
Withdrawn. The last approved version of this historical standard is referenced
factors that can affect how materials perform. This test method
on www.
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.

This May Also Interest You

ASTM
ASTM G99-23(Test Method)
Standard Test Method for Wear and Friction Testing with a Pin-on-Disk or Ball-on-Disk Apparatus

SIGNIFICANCE AND USE
5.1 The amount of wear in any system will, in general, depend upon the number of system factors such as the applied load, machine characteristics, sliding speed, sliding distance, the environment, and the material properties. The value of any wear test method lies in predicting the relative ranking of material combinations. Since the pin-on-disk test method does not attempt to duplicate all the conditions that may be experienced in service (for example, lubrication, load, pressure, contact geometry, removal of wear debris, and presence of corrosive environment), there is no insurance that the test will predict the wear rate of a given material under conditions differing from those in the test.  
5.2 The use of this test method will fall in one of two categories: (1) the test(s) will follow all particulars of the standard, and the results will have been compared to the ILS data (Table 2), or (2) the test(s) will have followed the procedures/methodology of Test Method G99 but applied to other materials or using other parameters such as load, speed, materials, etc., or both. In this latter case, the results cannot be compared to the ILS data (Table 2). Further, it must be clearly stated what choices of test parameters/materials were chosen.
SCOPE
1.1 This test method covers a laboratory procedure for determining the wear of materials and friction during sliding using a pin-on-disk apparatus. Materials are tested in pairs under nominally non-abrasive conditions. The principal areas of experimental attention in using this type of apparatus to measure wear are described.  
1.2 This test method standard uses a specific set of test parameters (load, sliding speed, materials, etc.) that were then used in an interlaboratory study (ILS), the results of which are given here (Tables 1 and 2). (This satisfies the ASTM form in that “The directions for performing the test should include all of the essential details as to apparatus, test specimen, procedure, and calculations needed to achieve satisfactory precision and bias.”) Any user should report that they “followed the requirements of ASTM G99,” where that is true.  
1.3 Now it is often found in practice that users may follow all instructions given here, but choose other test parameters, such as load, speed, materials, environment, etc., and thereby obtain different test results. Such a use of this standard is encouraged as a means to improve wear testing methodology. However, it must be clearly stated in any report that, while the directions and protocol in Test Method G99 were followed (if true), the choices of test parameters were different from Test Method G99 values, and the test results were therefore also different from the Test Method G99 results. This use should be described as having “followed the procedure of ASTM G99.” All test parameters that were used in such case must be stated.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Standard
    6 pages
    English language
    sale 15% off
  • Standard
    6 pages
    English language
    sale 15% off
ASTM
ASTM G98-23(Test Method)
Standard Test Method for Galling Resistance of Materials

SIGNIFICANCE AND USE
5.1 This test method is designed to rank material couples in their resistance to the failure mode caused by galling and not merely to classify the surface appearance of sliding surfaces.  
5.2 This test method should be considered when damaged (galled) surfaces render components non-serviceable. Experience has shown that galling is most prevalent in sliding systems that are slow moving and operate intermittently. The galling and seizure of threaded components is a classic example which this test method most closely simulates.  
5.3 Other galling-prone examples include: sealing surfaces of value trim which may leak excessively due to galling; and pump wear rings that may function ineffectively due to galling.  
5.4 If the equipment continues to operate satisfactorily and loses dimension gradually, then mechanical wear should be evaluated by a different test such as the crossed cylinder Test Method (see Test Method G83). Chain belt pins and bushings are examples of this type of problem.  
5.5 This test method should not be used for quantitative or final design purposes since many environmental factors influence the galling performance of materials in service. Lubrication, alignment, stiffness and geometry are only some of the factors that can affect how materials perform. This test method has proven valuable in screening materials for prototypical testing that more closely simulates actual service conditions.
SCOPE
1.1 This test method covers a laboratory test which ranks the galling resistance of material couples. Most galling studies have been conducted on bare metals and alloys; however, non-metallics, coatings, and surface modified alloys may also be evaluated by this test method.  
1.2 This test method is not designed for evaluating the galling resistance of material couples sliding under lubricated conditions because galling usually will not occur under lubricated sliding conditions using this test method.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Standard
    4 pages
    English language
    sale 15% off
  • Standard
    4 pages
    English language
    sale 15% off
ASTM
ASTM G223-23(Test Method)
Standard Test Method for Measuring Friction and Adhesive Wear Properties of Lubricated and Nonlubricated Materials Using the Twist Compression Test (TCT)

SIGNIFICANCE AND USE
5.1 This test method is designed to rank material couples, surface treatments, and lubricants by CFT and in their resistance to adhesive wear. Since adhesive wear is a complex phenomenon and stochastic in nature, it is essential to evaluate surfaces to confirm the presence of adhesion.  
5.2 This test method should be considered when evaluating the impact of changes in a process or application that is prone to adhesive wear, including any combination of scoring, galling, and plowing. These modes of failure commonly occur under sliding contact, at high contact stress, and, when applicable, at lubricant starvation.  
5.3 The TCT is often used to evaluate the ability of material couples, surface treatments, coatings, and lubricants to prevent or reduce adhesive wear in metalworking operations including deep drawing, extrusion, and pipe bending. Other applications in which the test may be effective are loader bucket bushings, gear teeth at startup, and low-clearance pumps.  
5.4 This test method is best used as a comparative screening tool. The ranking of performance produced by the TCT correlates well with the ranking in many applications.3 However, since the test is a bench test and not directly reproducing any specific application, TCT results should be only used as an indicator of the tendency for adhesive wear to occur. TCT is a useful screening test for comparing the effectiveness of material couples, surface treatments, coatings, and lubricant formulations before process testing and field trials.
SCOPE
1.1 This test method covers laboratory procedures for determining the coefficient of friction (COF) and resistance of materials to adhesion under flat sliding using the twist compression test (TCT). This test method ranks material couples, surface treatments, coatings, and lubricant combinations by COF and their resistance to adhesion.  
1.2 The time until adhesion for the materials under the test conditions are reported and used to quantify the tribocouple’s adhesion resistance and susceptibility to galling or scuffing. Systems of higher adhesion resistance will give longer time until failure.  
1.3 The coefficient of friction values averaged between the test reaching full test pressure and the time of the onset of adhesion or the end of tests run for a predetermined time period are recorded. Systems are ranked by their average coefficients of friction before adhesion occurs.  
1.4 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard except psi and pounds in Table 1.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Standard
    9 pages
    English language
    sale 15% off
ASTM
ASTM G75-15(2021)(Test Method)
Standard Test Method for Determination of Slurry Abrasivity (Miller Number) and Slurry Abrasion Response of Materials (SAR Number)

SIGNIFICANCE AND USE
5.1 The Miller Number5 is an index of the relative abrasivity of slurries. Its primary purpose is to rank the abrasivity of slurries in terms of the wear of a standard reference material. The wear damage on the standard wear block is worse as the Miller Number gets higher.  
5.2 The SAR Number is an index of the relative abrasion response of materials as tested in any particular slurry of interest. The SAR Number is a generalized form of the Miller Number applicable to materials other than the reference material used for the Miller Number determination. A major purpose is to rank construction materials for use in a system for pumping and fluid handling equipment for a particular slurry. It can also be used to rank the abrasivity of various slurries against any selected construction material other than the reference material specified for a Miller Number determination. The slurry damage on the specimen of material being tested is worse as the SAR Number gets higher.  
5.3 Experience has shown that slurries with a Miller Number or a SAR Number of approximately 50 or lower can be pumped with minor abrasive damage to the system. Above a number of 50, precautions must be observed and greater damage from abrasion is to be expected. Accordingly, the Miller Number and the SAR Number provide information about the slurry or the material that may be useful in the selection of pumps and other equipment and to predict the life expectancy of liquid-end parts of the pumps involved.  
5.4 The SAR Number can be used to determine the most suitable materials for certain slurry systems.
SCOPE
1.1 This test method covers a single laboratory procedure that can be used to develop data from which either the relative abrasivity of any slurry (Miller Number) or the response of different materials to the abrasivity of different slurries (SAR Number), can be determined.  
1.2 The test data obtained by this procedure is used to calculate either a number related to the rate of mass loss of duplicate standard-shaped 27 % chromium iron wear blocks when run for a period of time in the slurry of interest (Miller Number), or to calculate a number related to the rate of mass loss (converted to volume loss) of duplicate standard-shaped wear specimens of any material of interest when run for a period of time in any slurry of interest (SAR Number).  
1.3 The requirement for a finished flat wearing surface on the test specimen for a SAR Number test may preclude application of the procedure where thin (0.051 mm to 0.127 mm), hard, wear-resistant coatings will not allow for surface finishing. The 6 h total duration of the SAR Number Test may not allow establishment of a consistent rate-of-mass-loss of the unfinished surface.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Standard
    21 pages
    English language
    sale 15% off
ASTM
ASTM G65-16(2021)(Test Method)
Standard Test Method for Measuring Abrasion Using the Dry Sand/Rubber Wheel Apparatus

SIGNIFICANCE AND USE
5.1 The severity of abrasive wear in any system will depend upon the abrasive particle size, shape, and hardness, the magnitude of the stress imposed by the particle, and the frequency of contact of the abrasive particle. In this practice these conditions are standardized to develop a uniform condition of wear which has been referred to as scratching abrasion (1 and 3). The value of the practice lies in predicting the relative ranking of various materials of construction in an abrasive environment. Since the practice does not attempt to duplicate all of the process conditions (abrasive size, shape, pressure, impact, or corrosive elements), it should not be used to predict the exact resistance of a given material in a specific environment. Its value lies in predicting the ranking of materials in a similar relative order of merit as would occur in an abrasive environment. Volume loss data obtained from test materials whose lives are unknown in a specific abrasive environment may, however, be compared with test data obtained from a material whose life is known in the same environment. The comparison will provide a general indication of the worth of the unknown materials if abrasion is the predominant factor causing deterioration of the materials.
SCOPE
1.1 This test method covers laboratory procedures for determining the resistance of metallic materials to scratching abrasion by means of the dry sand/rubber wheel test. It is the intent of this test method to produce data that will reproducibly rank materials in their resistance to scratching abrasion under a specified set of conditions.  
1.2 Abrasion test results are reported as volume loss in cubic millimetres for the particular test procedure specified. Materials of higher abrasion resistance will have a lower volume loss.  
Note 1: In order to attain uniformity among laboratories, it is the intent of this test method to require that volume loss due to abrasion be reported only in the metric system as cubic millimetres. 1 mm3 = 6.102 × 10−5 in.3.  
1.3 This test method covers five recommended procedures which are appropriate for specific degrees of wear resistance or thicknesses of the test material.  
1.3.1 Procedure A—This is a relatively severe test which will rank metallic materials on a wide volume loss scale from low to extreme abrasion resistance. It is particularly useful in ranking materials of medium to extreme abrasion resistance.  
1.3.2 Procedure B—A short-term variation of Procedure A. It may be used for highly abrasive resistant materials but is particularly useful in the ranking of medium- and low-abrasive-resistant materials. Procedure B should be used when the volume–loss values developed by Procedure A exceeds 100 mm3.  
1.3.3 Procedure C—A short-term variation of Procedure A for use on thin coatings.  
1.3.4 Procedure D—This is a lighter load variation of Procedure A which is particularly useful in ranking materials of low-abrasion resistance. It is also used in ranking materials of a specific generic type or materials which would be very close in the volume loss rates as developed by Procedure A.  
1.3.5 Procedure E—A short-term variation of Procedure B that is useful in the ranking of materials with medium- or low-abrasion resistance.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Standard
    14 pages
    English language
    sale 15% off
ASTM
ASTM G211-14(2020)(Test Method)
Standard Test Method for Conducting Elevated Temperature Erosion Tests by Solid Particle Impingement Using Gas Jets

SIGNIFICANCE AND USE
5.1 The significance of this test method in any overall measurements program to assess the erosion behavior of materials will depend on many factors concerning the conditions of service applications. The users of this test method should determine the degree of correlation of the results obtained with those from field performance or results using other test systems and methods. This test method may be used to rank the erosion resistance of materials under the specified conditions of testing.
SCOPE
1.1 This test method is concerned with the determination of material loss by gas-entrained solid particle impingement erosion with jet nozzle type erosion equipment. This test method can be used in the laboratory to measure the solid particle erosion of different materials and has been used as a screening test for ranking solid particle erosion rates of materials in simulated service environments. Erosion service takes place under conditions where particle sizes, chemistry, microstructure, velocity, attack angles, temperature, environments, etc., vary over a wide range. Hence, any single laboratory test may not be sufficient to evaluate expected service performance. This test method describes one well characterized procedure for solid particle impingement erosion measurement for which interlaboratory test results are available from multiple laboratories.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Standard
    15 pages
    English language
    sale 15% off
ASTM
ASTM G81-97a(2018)(Test Method)
Standard Test Method for Jaw Crusher Gouging Abrasion Test

SIGNIFICANCE AND USE
5.1 A number of types of jaw crushers have been used for laboratory abrasion tests, see Refs (1-5)4 and a limited amount of data has been published (6-10). With emphasis on the crusher described in Section 6, this test method ranks materials and also indicates differences in wear life for that type of abrasion defined as gouging abrasion, as is found in crushing equipment and in many mining and earthmoving applications. This test method is considered useful for research and development purposes, but not to specify universal wear ratios, since the wear ranking and severity of wear may change dramatically with a change of the characteristics (chemistry, shape, angularity, etc.) of the crushed material or type of machinery.
SCOPE
1.1 This test method covers a laboratory procedure to determine the relative gouging abrasion resistance of materials. Materials homogeneous in structure and properties are the most appropriate test materials; however, surface-treated and composite materials can also be tested. The test involves a small laboratory jaw crusher that crushes presized hard rock materials, such as a hard morainal gravel, or some other crushable substance.  
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. (See 8.1 on Safety Precautions.)  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Standard
    7 pages
    English language
    sale 15% off
ASTM
ASTM G115-10(2018)(Guide)
Standard Guide for Measuring and Reporting Friction Coefficients

SIGNIFICANCE AND USE
5.1 In this guide, factors that shall be considered in conducting a valid test for the determination of the coefficient of friction of a tribosystem are covered, and the use of a standard reporting format for friction data is encouraged.  
5.2 The factors that are important for a valid test may not be obvious to non-tribologists, and the friction tests referenced will assist in selecting the apparatus and test technique that is most appropriate to simulate a tribosystem of interest.  
5.3 The tribology literature is replete with friction data that cannot readily be used by others because specifics are not presented on the tribosystem that was used to develop the data. The overall goal of this guide is to provide a reporting format that will enable computer databases to be readily established. These databases can be searched for material couples and tribosystems of interest. Their use will significantly reduce the need for each laboratory to do its own testing. Sufficient information on test conditions will be available to determine applicability of the friction data to the engineer's specific needs.
SCOPE
1.1 This guide covers information to assist in the selection of a method for measuring the frictional properties of materials. Requirements for minimum data and a format for presenting these data are suggested. The use of the suggested reporting form will increase the long-term usefulness of the test results within a given laboratory and will facilitate the exchange of test results between laboratories. It is hoped that the use of a uniform reporting format will provide the basis for the preparation of handbooks and computerized databases.  
1.2 This guide applies to most solid materials and to most friction measuring techniques and test equipment.  
1.3 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Guide
    13 pages
    English language
    sale 15% off
ASTM
ASTM G194-08(2018)(Test Method)
Standard Test Method for Measuring Rolling Friction Characteristics of a Spherical Shape on a Flat Horizontal Plane

SIGNIFICANCE AND USE
5.1 Rolling friction like sliding friction depends upon many factors. It is a system effect that involves the nature of the rolling surface and the counterface. The sliding friction force (F) is usually considered to be the sum of forces arising from deformations of surface features (Fs), from attractive forces (atomic, molecular, etc.) at contact points (Fa) and force from interaction of films and particulates on the rubbing surfaces (Ff):
The rolling friction force includes these force contributions plus effects from the relative stiffness of the contacting surfaces, the diameter (curvature) of the spherical shape (ball, orange, etc.) and other factors. Because there are so many factors involved in a rolling tribosystem, rolling resistance can best be quantified by an actual test of the sphere of interest on the intended counterface, as in this test method.  
5.2 There are countless applications where it is important to quantify the rolling characteristics of a particular spherical shape on a particular surface. The interlaboratory tests conducted for this test method were performed on hardened steel balls like those used in ball bearings. This test method could be used to assess the effect of different counterface surfaces on the rolling characteristics of balls for ball bearings. Conversely, it could be used as a quality control test on balls. Surface imperfections/defects/films, etc. on the balls can affect how they roll: the distance traveled on a common counterface.  
5.3 Industrial applications of this test method can include assessing conveying surfaces for spherical or nearly special parts: check valve balls, cabinet knobs, Christmas ornaments, toilet floats, etc. Many medical devices use special shapes where rolling characteristics are a consideration. Similarly, many pharmaceutical products (pills) are spherical or nearly spherical in shape, and this test method can be used to assess rolling characteristics for conveying or other reasons such ...
SCOPE
1.1 This test method covers the use of an angled launch ramp to initiate rolling of a sphere or nearly spherical shape on a flat horizontal surface to determine the rolling friction characteristics of a given spherical shape on a given surface.  
1.1.1 Steel balls on a surface plate were used in interlaboratory tests (see Appendix X1). Golf balls on a green, soccer and lacrosse balls on playing surfaces, bowling balls on an a lane, basketballs on hardwood, and marbles on composite surface were tested in the development of this test method, but the test applies to any sphere rolling on any flat horizontal surface.  
1.1.2 The rolling friction of spheres on horizontal surfaces is affected by the spherical shape’s stiffness, radius of curvature, surface texture, films on the surface, the nature of the counterface surface; there are many factors to consider. This test method takes all of these factors into consideration. The spherical shape of interest is rolled on the surface of interest using a standard ramp to initiate rolling and standard techniques to measure and treat the rolled distance after leaving the ramp.  
1.1.3 This test method produces a rolling resistance number on a specific spherical shape on a specific surface. It is intended for comparing similar tribosystems. For example, the rolling resistances of marbles on a particular surface are not to be compared with the rolling resistance of soccer balls on grass, because their masses and diameters are very different as are the counterface surfaces on which they roll.  
1.1.4 Different launch ramps are appropriate for different types of spherical shapes. If a sphere of interest cannot be accommodated with using one of the launch ramps discussed in Appendix X1 and Appendix X2, a different launch ramp can be developed and added with future revisions to this test method.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measu...

  • Standard
    9 pages
    English language
    sale 15% off
ASTM
ASTM G171-03(2017)(Test Method)
Standard Test Method for Scratch Hardness of Materials Using a Diamond Stylus

SIGNIFICANCE AND USE
5.1 This test method is intended to measure the resistance of solid surfaces to permanent deformation under the action of a single point (stylus tip). It is a companion method to quasi-static hardness tests in which a stylus is pressed into a surface under a certain normal load and the resultant depth or impression size is used to compute a hardness number. Scratch hardness numbers, unlike quasi-static hardness numbers, involve a different combination of properties of the surface because the indenter, in this case a diamond stylus, moves tangentially along the surface. Therefore, the stress state under the scratching stylus differs from that produced under a quasi-static indenter. Scratch hardness numbers are in principle a more appropriate measure of the damage resistance of a material to surface damage processes like two-body abrasion than are quasi-static hardness numbers.  
5.2 This test method is applicable to a wide range of materials. These include metals, alloys, and some polymers. The main criteria are that the scratching process produces a measurable scratch in the surface being tested without causing catastrophic fracture, spallation, or extensive delamination of surface material. Severe damage to the test surface, such that the scratch width is not clearly identifiable or that the edges of the scratch are chipped or distorted, invalidates the use of this test method to determine a scratch hardness number. Since the degree and type of surface damage in a material may vary with applied load, the applicability of this test to certain classes of materials may be limited by the maximum load at which valid scratch width measurements can be made.  
5.3 The resistance of a material to abrasion by a single point may be affected by its sensitivity to the strain rate of the deformation process. Therefore, this test is conducted under low stylus traversing speeds. Use of a slow scratching speed also minimizes the possible effects of frictional heating.  
5.4 This...
SCOPE
1.1 This test method covers laboratory procedures for determining the scratch hardness of the surfaces of solid materials. Within certain limitations, as described in this guide, this test method is applicable to metals, ceramics, polymers, and coated surfaces. The scratch hardness test, as described herein, is not intended to be used as a means to determine coating adhesion, nor is it intended for use with other than specific hemispherically-tipped, conical styli.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Standard
    7 pages
    English language
    sale 15% off